Merge branch 'cassandra-2.0' into trunk

CHANGES.txt

@@ -17,6 +17,7 @@
 
 
 2.0.4
+ * Reduce gossip memory use by interning VersionedValue strings (CASSANDRA-6410)
  * Allow specifying datacenters to participate in a repair (CASSANDRA-6218)
  * Fix divide-by-zero in PCI (CASSANDRA-6403)
  * Fix setting last compacted key in the wrong level for LCS (CASSANDRA-6284)

conf/cassandra-env.sh

@@ -195,6 +195,9 @@ startswith() { [ "${1#$2}" != "$1" ]; }
 # Per-thread stack size.
 JVM_OPTS="$JVM_OPTS -Xss256k"
 
+# Larger interned string table, for gossip's benefit (CASSANDRA-6410)
+JVM_OPTS="$JVM_OPTS -XX:StringTableSize=1000003"
+
 # GC tuning options
 JVM_OPTS="$JVM_OPTS -XX:+UseParNewGC" 
 JVM_OPTS="$JVM_OPTS -XX:+UseConcMarkSweepGC" 

src/java/org/apache/cassandra/gms/VersionedValue.java

@@ -80,7 +80,11 @@ public class VersionedValue implements Comparable<VersionedValue>
     private VersionedValue(String value, int version)
     {
         assert value != null;
-        this.value = value;
+        // blindly interning everything is somewhat suboptimal -- lots of VersionedValues are unique --
+        // but harmless, and interning the non-unique ones saves significant memory.  (Unfortunately,
+        // we don't really have enough information here in VersionedValue to tell the probably-unique
+        // values apart.)  See CASSANDRA-6410.
+        this.value = value.intern();
         this.version = version;
     }